I should note that I do use a workaround: * Take a heightmap of a sculpted sloping terrain, by your usual means. Save it as (UV-unwrapped) mesh terrain file (.obj or .fbx). * Extract a heightmap of the mesh terrain, by some means (I personally created a makeshift "heightmap template" to do this quicker in Blender). * Take…
I'm a bit late here, but I know of at least three tools that can achieve what you're seeking (because I need them for the same purpose as yourself): Mari has a slope angle-based texturing capability--I've seen it used on a Digital Tutors tutorial once. L3DT lets you do angle-based texturing procedurally (though, you…